Solid electrolyte-secondary particle composites

ABSTRACT

Composite anode-active particulates that include lithium-active, silicon nanoparticles in carbon matrices impregnated with solid electrolyte are described with methods for their preparation. The composite active particulates preferably include a solid electrolyte phase carried within pores of the particulate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This disclosure claims the benefit of priority to U.S. PatentApplication No. 63/021,235, filed May 7, 2020, the entirety of which areincorporated herein.

FIELD OF THE INVENTION

Embodiments of the present invention relate to the structure,preparation, and use of particulates which include anode-activenanoparticles and solid electrolytic materials in lithium ion batteries.

BACKGROUND

Lithium-ion (Li⁺) secondary or rechargeable batteries are now the mostwidely used secondary battery systems for portable electronic devices.However, the growth in power and energy densities for lithium ionbattery technology has stagnated in recent years as materials thatexhibit both high capacities and safe, stable cycling have been slow tobe developed. Much of the current research effort for the nextgeneration of higher energy capacity materials has revolved around usingsmall or nanoparticulate active material bound together with conductiveagents and carbonaceous binders.

There is a current and growing need for higher power and energy densitybattery systems. The power requirements for small scale devices such asmicroelectromechanical systems (MEMS), small dimensional sensor systems,and integrated on-chip microelectronics exceed the power densities ofcurrent Li⁺ based energy storage systems. Power densities of at least 1J/mm² are desired for effective function for such systems, and currentenergy densities for Li⁺ thin film battery systems are about 0.02 J/mm².Three dimensional architectures for battery design can improve the arealpower density of Li⁺ secondary batteries by packing more active materialper unit area without employing thicker films that are subject toexcessive cycling fatigue. Three-dimensional Lithium-ion batteryarchitectures also increase lithium ion diffusion by maximizing thesurface area to volume ratio and by reducing diffusion lengths.

The current state-of-the-art for anode electrodes in lithium ionbatteries includes the use of high surface area carbon materials.However, the capacity of any graphitic carbon, carbon black, or othercarbonaceous material is limited to a theoretical maximum of 372 mAh/gand about 300 mAh/g in practice because carbon electrodes are usuallyformed of carbon particles mixed with a polymeric binder pressedtogether to form a bulk electrode. To store charge, Li⁺ intercalatesbetween the planes of sp² carbon atoms and this C—Li⁺—C moiety isreduced. In addition, the maximum number of Li⁺ that can be stored isone per every six carbon atoms (LiC₆). While the capacity of graphiticcarbon is not terribly high, the intercalation process preserves thecrystal structure of the graphitic carbon, and so cycle life can be verygood.

A more recent and promising option for anode materials is silicon (Si).In contrast to the intercalative charge storage observed in graphite, Siforms an alloy with lithium. Silicon-based negative electrodes areattractive because their high theoretical specific capacity of about4200 mAh/g, which far exceeds than that of carbon, and is second only topure U metal. This high capacity comes from the conversion of the Sielectrode to a lithium silicide which at its maximum capacity has aformula of Li₂₂Si₆, storing over 25 times more Li per atom than carbon.The large influx of atoms upon alloying, however, causes volumetricexpansion of the Si electrode of over 400%. This expansion causes strainin the electrode, and this strain is released by formation of fracturesand eventual electrode failure. Repeated cycling between Li_(x)Si_(y)and Si thus causes crumbling of the electrode and loss ofinterconnectivity of the material. For example, 1 μm thick Si filmanodes have displayed short cyclability windows, with a precipitouslycapacity drop after only 20 cycles. Accordingly, new structures forsilicon compositions and silicon containing laminates are needed.

SUMMARY

A first embodiment is a composite active particulate that includes anadmixture of a heterogeneous matrix and a solid-electrolytic phase; theheterogeneous matrix includes a carbon phase carrying and/or havingembedded therein a plurality of silicon nanoparticles, and a pluralityof pores therewithin; and where the solid-electrolytic phase is carriedwithin the pores of the heterogeneous matrix.

A second embodiment is a composite laminate carried on a currentcollector, the composite laminate includes an admixture of aheterogeneous matrix and a solid-electrolytic phase; the heterogeneousmatrix includes a carbon phase carrying and/or having embedded therein aplurality of silicon nanoparticles, and a plurality of porestherewithin; and where the solid-electrolytic phase is carried withinthe pores of the heterogeneous matrix carried in solid-electrolyticcontinuous phase.

A third embodiment is a process for preparing a composite activeparticulate that includes providing an active particulate that includesa porous heterogeneous matrix, the porous heterogeneous matrix includinga carbon phase carrying and/or having embedded therein a plurality ofsilicon nanoparticles, and a plurality of pores therewithin; providing asolution which includes a polysulfide, a solid-electrolyte particulate,and a solvent; admixing the active particulate and the solution therebyallowing the solution to penetrate pores of the active particulate; andthereafter removing the solvent.

A fourth embodiment is a process for preparing an anode that includesproviding a plurality of active particulates that include a porousheterogeneous matrix, the porous heterogeneous matrix including a carbonphase carrying and/or having embedded therein a plurality of siliconnanoparticles, and a plurality of pores therewithin; providing asolution which includes a polysulfide, a solid-electrolyte particulate,and a solvent; admixing the active particulate and the solution therebyallowing the solution to penetrate pores of the active particulate;thereafter coating a current collector with the admixture of the activeparticulate and the solution thereby forming a coating on the currentcollector; and then removing the solvent from the coating on the currentcollector and thereby providing a composite laminate that includescomposite active particulates in a solid-electrolytic continuous phasecarried on the current collector, wherein the composite activeparticulates include a solid-electrolytic phase carried within the poresof the porous heterogeneous matrix, and wherein the solid-electrolyticphase is covalently affixed to the solid-electrolytic continuous phase.

BRIEF DESCRIPTION OF THE FIGURES

For a more complete understanding of the disclosure, reference should bemade to the following detailed description and accompanying drawingfigures wherein:

FIG. 1 is a first schematic of a process described herein; and

FIG. 2 is a second schematic of a process described herein.

While specific embodiments are illustrated in the figures, with theunderstanding that the disclosure is intended to be illustrative, theseembodiments are not intended to limit the invention described andillustrated herein.

DETAILED DESCRIPTION

Objects, features, and advantages of the present invention will becomeapparent from the following detailed description. It should beunderstood, however, that the detailed description and the specificexamples, while indicating specific embodiments of the invention, aregiven by way of illustration only, since various changes andmodifications within the spirit and scope of the invention will becomeapparent to those skilled in the art from this detailed description.

Herein, the use of the word “a” or “an” when used in conjunction withthe term “comprising” in the claims and/or the specification may mean“one,” but it is also consistent with the meaning of “one or more,” “atleast one,” and “one or more than one.” The term “about” means, ingeneral, the stated value plus or minus 5%. The use of the term “or” inthe claims is used to mean “and/or” unless explicitly indicated to referto alternatives only or the alternative are mutually exclusive, althoughthe disclosure supports a definition that refers to only alternativesand “and/or.” Ranges include all specific values and subrangestherebetween.

Herein are described products and processes which feature anode activematerials and solid electrolytes or solid-electrolytic phases. Oneembodiment is a composite active particulate that includes a porousheterogeneous matrix and a solid-electrolytic phase. The porousheterogeneous matrix preferably includes a carbon phase carrying aplurality of silicon nanoparticles, where the carbon phase and siliconnanoparticles define a plurality of pores and a pore volume within theporous heterogeneous matrix. The solid-electrolytic phase is thencarried within the pores of the porous heterogeneous matrix and adjacentto silicon nanoparticles.

In one instance, the composite active particulates have an averagediameter of about 1 μm to about 100 μm. Preferably, composite activeparticulates have an average diameter of about 2 μm to about 75 μm,about 3 μm to about 65 μm, about 4 μm to about 50 μm, about 5 μm toabout 30 μm, or about 5 μm to about 25 μm.

The composite active particulate is preferably an anode active materialuseful for lithium ion storage and release in a lithium-ion battery.Accordingly, the composite active material preferably has bothelectrical conductivity and ionic conductivity. In a preferableinstance, the composite active particulate has a particle electricalconductivity in a range of about 10⁴ to about 10⁵ S/cm, about 10⁻³ toabout 10⁵ S/cm, about 10⁻² to about 10⁵ S/cm, about 10⁻³ to about 10⁴S/cm, about 10⁻³ to about 10³ S/cm, about 10⁻² to about 10⁵ S/cm, about0.1 to about 10⁵ S/cm, or about 1 to about 10⁵ S/cm. Still further, thecomposite active particulate, preferably, has a particle ionicconductivity in a range of about 10⁻⁶ to about 10⁻¹ S/cm, about 10⁻⁵ toabout 10⁻¹ S/cm, about 10⁻⁴ to about 10⁻¹ S/cm, or about 10⁻³ to about10⁻¹ S/cm. More preferably, the particle ionic conductivity is greaterthan about 10⁻⁵, about 10⁻⁴, about 10⁻³, of about 10⁻² S/cm.

In one instance, the solid-electrolytic phase occupies between about 10%and about 50% of the pore volume as defined by the porous heterogeneousmatrix. In another instance, the porous heterogeneous matrix has a porevolume equal to or greater than a silicon nanoparticle volume. In oneexample, the pore volume is at least 100%, 125%, 150%, 175%, 200%, 225%,250%, 275%, or 300% of the silicon nanoparticle volume. While thesolid-electrolytic phase can occupy/fill up to 100% of the pore volume,the composite active particulate, preferably, has sufficientunoccupied/open pore volume to accommodate a lithiated silicon speciesgenerated during the charge/discharge cycle of a lithium ion battery.Herewith, the composite active particulate preferably has an open porevolume of about 0.01 to about 0.2 cm³/g, whereas the porousheterogeneous matrix had, prior to the addition of thesolid-electrolytic phase a pore volume of about 0.01 to about 0.25cm³/g.

Examples of porous heterogeneous matrices useful herein, include but arenot limited to those described in U.S. Pat. Nos. 10,590,277, 10,476,071,10,454,103, 10,195,583, 10,147,950, 10,461,325, 10,461,320, 10,608,240,9,673,448, 9,373,838, 8,889,295, and US Pat. Pub. 2018/0145316, thedisclosures of which are incorporated herein.

In one example, the carbon phase can be a soft carbon; in anotherexample, the carbon phase can be a hard carbon. In still anotherexample, the carbon phase is an admixture of soft and hard carbon.Preferably, the carbon phase is electronically conductive; that is, thecarbon phase conducts electrons to and from the silicon nanoparticlescarried within the composite active particulate to a surface of thecomposite active particulate. In a particular instance, the carbon phasecan have an electrical conductivity in a range of about 10⁻⁴ to about10⁵ S/cm, about 10⁻³ to about 10⁵ S/cm, about 10⁻² to about 10⁵ S/cm,about 10⁻³ to about 10⁴ S/cm, about 10⁻³ to about 10³ S/cm, about 10⁻²to about 10⁵ S/cm, about 0.1 to about 10⁵ S/cm, or about 1 to about 10⁵S/cm.

The carbon phase can include, consists essentially of, or consist ofreduced carbon. As used herein and as represented in the heterogeneousmatrix, reduced carbon, i.e., elemental carbon, and can be an amorphouscarbon, graphite, graphene, porous carbon, diamond, other polymorph, ormixture thereof. The reduced carbon is typically a thermally processedorganic compound, e.g., a carbon matrix precursor, that is treated at atemperature and pressure that converts the organic compound to inorganiccarbon (elemental carbon and its polymorphs). Typically, reduced carbon(phase) is insufficiently conductive for the use of the material inbattery applications, accordingly, the carbon phase can further includea conductive carbon. The conductive carbon can be selected from carbonnanotubes, carbon nanofibers, C65, C45, graphene, graphene oxide,reduced graphene oxide, mesocarbon microbeads, or a mixture thereof.Specific examples include Super P (e.g., MTI), Super C65 (e.g., IMERY),Super C45 (e.g., IMERY), TIMREX KS6 (e.g., MTI), and KS6L (e.g., IMERY).Preferably, the composite active particulate includes about 1 wt. %, 2wt. %, 2.5 wt. %, 3 wt. %, 3.5 wt. %, 4 wt. %, 4.5 wt. %, 5 wt. %, 5.5wt. %, 6 wt. %, 6.5 wt. %, 7 wt. %, 7.5 wt. %, 8 wt. %, 8.5 wt. %, 9 wt.%, 9.5 wt. %, or 10 wt. % of the conductive carbon. In certaininstances, the carbon phase is an admixture of conductive carbon and thereduced carbon, and has an electrical conductivity in a range of about10⁻⁴ to about 10⁵ S/cm, about 10⁻³ to about 10⁵ S/cm, about 10⁻² toabout 10⁵ S/cm, about 10⁻³ to about 10⁴ S/cm, about 10⁻³ to about 10³S/cm, about 10⁻² to about 10⁵ S/cm, about 0.1 to about 10⁵ S/cm, orabout 1 to about 10⁵ S/cm.

The silicon nanoparticles, preferably, include greater than about 70 wt.%, 75 wt. %, 80 wt. %, 85 wt. %, 90 wt. %, about 95 wt. %, about 98 wt.%, about 99 wt. %, about 99.5 wt. %, or about 99.9 wt. % silicon. In oneinstance, the silicon nanoparticles consist essentially of silicon. Inanother instance, the silicon nanoparticles consist of amorphoussilicon. In one example, the silicon nanoparticles include amorphoushydrogenated silicon (a-Si:H). In another example, the siliconnanoparticles include n-doped or p-doped silicon.

In yet another example, the silicon nanoparticles include a siliconalloy. The silicon alloy can be a binary alloy (silicon plus onealloying element), can be a tertiary alloy, or can include a pluralityof alloying elements. The silicon alloy is understood to include amajority silicon. A majority silicon means that the nanoparticles have aweight percentage that is greater than about 50% (50 wt. %) silicon,preferably greater than about 60 wt. %, 70 wt. %, 80 wt. %, 90 wt. %, 95wt. %, 96 wt. %, 97 wt. %, 98 wt. %, 99 wt. %, or 99.5 wt. % silicon.The alloying element can be, for example, an alkali metal, analkaline-earth metal, a Group 13 to 16 element, a transition metal groupelement, a rare earth group element, or a combination thereof, but,obviously, not Si. The alloying element can be, for example, Li, Na, Mg,Ca, Sc, Y, Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, Mn, Re, Fe, Ru, Os, Co, Rh,Ir, Ni, Pd, Pt, Cu, Ag, Au, Zn, Cd, B, Al, Ga, In, Ge, Sn, P, As, Sb,Bi, S, Se, Te, or a combination thereof. In one instance, the alloyingelement can be lithium, magnesium, aluminum, titanium, vanadium,chromium, manganese, iron, cobalt, nickel, copper, or a mixture thereof.In another instance, the alloying element can be selected from copper,silver, gold, or a mixture thereof. In still another instance, thesilicon alloy can be selected from a SiTiNi alloy, a SiAlMn alloy, aSiAlFe alloy, a SiFeCu alloy, a SiCuMn alloy, a SiMgAl alloy, a SiMgCualloy, or a combination thereof.

As the term alloy typically infers a homogeneous distribution of thealloying element(s) in the base material, silicon, the siliconnanoparticles can further include a heterogeneous distribution ofalloying elements in the nanoparticles. In some instances, these alloyelements form intermetallics in the silicon nanoparticles. Anintermetallic (also called an intermetallic compound, intermetallicalloy, ordered intermetallic alloy, and a long-range-ordered alloy) isan alloy that forms a solid-state compound exhibiting definedstoichiometry and ordered crystal structure; here, within the amorphoussilicon nanoparticle composition (e.g., a NiSi intermetallic within Si).

The silicon nanoparticles, preferably, have an average diameter of lessthan about 1,000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 400 nm, 300nm, or 250 nm. In another instance, the silicon nanoparticles have anaverage diameter of from about 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm,40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90nm, or 100 nm to about 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm,400 nm, 450 nm, 500 nm, 550 nm, 600 nm, 650 nm, 700 nm, 750 nm, 800 nm,850 nm, 900 nm, 950 nm, or 1,000 nm. In specific instances, the siliconnanoparticles have an average diameter of about 50 nm to about 1,000 nm,about 50 nm to about 800 nm, about 50 nm to about 750 nm, about 50 nm toabout 700 nm, about 50 nm to about 650 nm, about 50 nm to about 600 nm,about 50 nm to about 550 nm, about 50 nm to about 500 nm, about 50 nm toabout 450 nm, about 50 nm to about 400 nm, about 50 nm to about 350 nm,about 50 nm to about 300 nm, about 100 nm to about 750 nm, about 100 nmto about 600 nm, about 100 nm to about 500 nm, about 100 nm to about 400nm, or about 100 nm to about 300 nm. In one instance, siliconnanoparticles have a spherical morphology. In another instance, thesilicon nanoparticles can have a plate-like morphology.

The solid-electrolytic phase is preferably a lithium metal sulfide, forexample a lithium borosulfide, a lithium phosphosulfide. In this use,the “metal” can be a transition metal element and/or a main groupelement. In one instance, the solid-electrolytic phase can have aformula of Li_(x)M_(y)S_(z) or Li_(x)M_(y)S_(z)R_(n) where M includes Band/or P, where R is a halide, and where x, y, z, and n are positiveintegers. The solid-electrolytic phase can further feature a formulawhere M further includes As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, Ta,and/or Zn; that is, in addition to B and/or P. Preferably, M includesSi, Sn, Ge, and/or Zn. Examples of lithium metal sulfide,solid-electrolytic phases include but are not limited toLi_(4-x)M_(1-x)M′_(x)S₄ wherein M is Si, Ge, or a mixture thereof, whereM′ is P, Al, Zn, Ga, or a mixture thereof, and where x is a value fromabout 0.1 to about 0.9; Li_(10+x)(Sn_(y)Si_(1-y))_(1+x)P_(2-X)S₁₂ wherex is from about 0 to about 2, and wherein y is from about 0 to 1;Li₆PS₅X where X is F, Cl, Br, I, or a mixture thereof;Li_(6+x)P_(1-x)Si_(x)S₅Br where x is from about 0 to 1;Li_(1+2x)Zn_(1-x)PS₄, wherein x is from about 0 to 1;Li_(7-x-2y)PS_(6-x-y)Cl_(x), where 0.8≤x≤1.7 and 0<y≤−0.25x+0.5;Li_(7-x+y)PS_(6-x)Cl_(x+y), where 0.05≤y≤0.9 and −3.0x+1.8≤y≤−3.0x+5.7;Li_(7-x)MS_(6-x)X_(x) where X is Cl or Br, M is P, B, or a mixturethereof, and x is 0.2 to 1.8; Li_(3x)[Li_(x)Sn_(1-x)S₂] where x is fromabout 0 to about 1; and Li_((12-n-x))B^(n+)X_(6-x)Y⁻ _(x), where B^(n+)is selected from the group consisting of P, As, Ge, Ga, Sb, Sn, Al, In,Ti, V, Nb and Ta; X is selected from the group consisting of S. Se andTe; and Y⁻ is selected from the group consisting of Cl, Br, I, F, CN,OCN, SCN, and N₃, while 0≤x≤2. Specific examples of lithium metalsulfide, solid-electrolytic phases include but are not limited toLi₉B₁₉S₃₃; Li₅B₇S₁₃; Li₂B₂S₅; Li₃BS₃; Li₇P₃S₁₁; Li₃PS₄;Li[Li_(0.33)Sn_(0.67)S₂]; Li_(0.6)[Li_(0.2)Sn_(0.8)S₂]; Li₁₁Si₂PS₁₂;Li_(9.54)Si_(1.74)P_(1.44)S_(11.7)Cl_(0.3); Li₁₀Si_(0.5)Ge_(0.5)P₂S₁₂;Li₁₀Sn_(0.5)Ge_(0.5)P₂S₁₂; Li₁₀Si_(0.5)Sn_(0.5)P₂S₁₂;Li₁₀GeP₂S_(11.7)O_(0.3); Li_(9.6)P₃S₁₂; Li₉P₃S₉O₃;Li_(10.35)Ge_(1.35)P_(1.65)S₁₂; Li_(10.35)Si_(1.35)P_(1.65)S₁₂;Li_(9.81)Sn_(0.81)P_(2.19)S₁₂;Li_(9.42)Si_(1.02)P_(2.1)S_(9.96)O_(2.04); Li₁₀GeP₂S₁₂; Li₁₃GeP₃S₁₂;Li₁₀SnP₂S₁₂, or mixtures thereof. Particularly preferable lithium metalsulfide, solid-electrolytic phases include Li_(x)M_(y)S_(z) where Mincludes B and/or P, where x, y, and z are positive integers; andLi_(x′)M_(y′)S_(x′)R_(n′) where M includes B and/or P, where R is ahalide, preferably selected from Cl and Br, and where x′, y′, z′, and n′are positive integers. Herewith, the values x, y, z, n, and the primesthereof are preferably positive integers and while somesolid-electrolytic phases are described in terms of fractional values,these are not exclusive; for example, Li_(9.6)P₃S₁₂ (included in theabove list) can be represented as Li₉₆P₃₀S₁₂₀, Li₁₆P₅S₂₀ or Li₁₆(PS₄)₅.

A second embodiment is a process for preparing a composite activeparticulate described above. That is, the process provides a compositeactive particulate which includes a porous heterogeneous matrix and asolid-electrolytic phase carried within the pores and adjacent tosilicon nanoparticles. The process, preferably, includes admixing asolution of a polysulfide and a solid-electrolyte particulate with anactive porous particulate, thereby impregnating pores of the activeporous particulate with the polysulfide and the solid-electrolyteparticulate. Preferably, the admixture includes a mass ratio of theactive porous particulate to the solid-electrolyte particulates of about10:1, about 9:1, about 8:1, about 7:1, about 6:1 about 5:1 about 4:1,about 3:1, about 2:1 on a dry basis. That is, on a dry mass basis, thereis a greater amount of the active porous particulate thansolid-electrolyte particulates. The active porous particulates can havean average diameter of about 1 μm to about 100 μm. Preferably, activeporous particulates have an average diameter of about 2 μm to about 75μm, about 3 μm to about 65 μm, about 4 μm to about 50 μm, about 5 μm toabout 30 μm, or about 5 μm to about 25 μm. Wherein the solid-electrolyteparticles, preferably, have an average particle diameter of about 5 nmto about 250 nm, or an average diameter of from about 5 nm, 10 nm, 15nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, 60 nm, 65nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, or 100 nm to about 100 nm, 150nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm, 500 nm.

Thereafter, the polysulfide and the solid-electrolyte particulate areconverted to the solid-electrolytic phase within the active porousparticulate. One instance includes providing an active particulate thatincludes a porous heterogeneous matrix. The porous heterogeneous matrix,preferably, includes a carbon phase carrying a plurality of siliconnanoparticles. Therein, the carbon phase and silicon nanoparticlesdefine a plurality of pores within the porous heterogeneous matrix.

The process can further include providing a solution of a polysulfide, asolid-electrolyte particulate, and a solvent. In one instance, thesolution can be provided by admixing the components. Notably, while theterm solution is used herein, the specific phase of the mixture can be aslurry. Preferably, all of the components dissolve in or have solubilityin the solvent. In another instance, the polysulfide stabilizes thedispersion of the solid-electrolyte particulates in the solvent.

The process can then further include admixing the active particulate andthe solution thereby allowing the solution to penetrate pores of theactive particulate. In one preferable instance, the active particulateis dry prior to admixing with the solution. In another instance, theactive particulate is slurried in the solvent or a second solvent priorto admixing with the solution. In still another instance, the activeparticulate is slurring in a solvent or second solvent with polysulfideprior to admixing with the solid-electrolyte particulate. In yet anotherinstance, the active particulate is wetted with a second solvent that isimmiscible in the solvent that is part of the solution; thereby when thewetted-active particulates is admixed with the solution, the solutiondoes not fully penetrate the pores of the active particulate. In stillanother instance, the active particulate and the solution are admixedand then exposed to a vacuum to reduce the localized pressure within thepores of the active particulate, and then the vacuum is broken therebydriving the solution into the pores.

The process can still further include removing the solvent and therebyproviding the composite active particulate. In one instance, the solventcan be removed by vacuum distillation. In another instance, the solventcan be removed by solvent exchange. In another instance, the solvent isremoved by distillation at an elevated (greater than 30° C.)temperature. Still further, the process can include heating thecomposite active particulate to a temperature of about 50° C. to about600° C., about 50° C. to about 500° C., about 50° C. to about 450° C.,about 75° C. to about 400° C., about 100° C. to about 400° C., about100° C. to about 350° C., or about 100° C. to about 300° C.

The solid-electrolytic phase is preferably a lithium metal sulfide, forexample a lithium borosulfide, a lithium phosphosulfide. In this use,the “metal” can be a transition metal element and/or a main groupelement. Examples of lithium metal sulfide, solid-electrolytic phasesinclude but are not limited to Li_(4-x)M_(1-x)M′_(x)S₄ wherein M is Si,Ge, or a mixture thereof, where M′ is P, Al, Zn, Ga, or a mixturethereof, and where x is a value from about 0.1 to about 0.9;Li_(10+x)(Sn_(y)Si_(1-y))_(1+x)P_(2-X)S₁₂ where x is from about 0 toabout 2, and wherein y is from about 0 to 1; Li₆PS₅X where X is F, Cl,Br, I, or a mixture thereof; Li_(6+x)P_(1-x)Si_(x)S₅Br where x is fromabout 0 to 1; Li_(1+2x)Zn_(1-x)PS₄, wherein x is from about 0 to 1;Li_(7-x-2y)PS_(6-x-y)Cl_(x), where 0.8≤x≤1.7 and 0<y≤−0.25x+0.5;Li_(7-x+y)PS_(6-x)Cl_(x+y), where 0.05≤y≤0.9 and −3.0x+1.8≤y≤−3.0x+5.7;Li_(7-x)MS_(6-x)X_(x) where X is Cl or Br, M is P, B, or a mixturethereof, and x is 0.2 to 1.8; Li_(3x)[Li_(x)Sn_(1-x)S₂] where x is fromabout 0 to about 1; and Li_((12-n-x))B^(n+)X_(6-x)Y⁻ _(x), where B^(n+)is selected from the group consisting of P, As, Ge, Ga, Sb, Sn, Al, In,Ti, V, Nb and Ta; X is selected from the group consisting of S, Se andTe; and Y⁻ is selected from the group consisting of Cl, Br, I, F, CN,OCN, SCN, and N₃, while 0≤x≤2. Specific examples of lithium metalsulfide, solid-electrolytic phases include but are not limited toLi₉B₁₉S₃₃; Li₅B₇S₁₃; Li₂B₂S₅; Li₃BS₃; Li₇P₃S₁₁; Li₃PS₄;Li[Li_(0.33)Sn_(0.67)S₂]; Li_(0.6)[Li_(0.2)Sn_(0.8)S₂]; Li₁₁Si₂PS₁₂;Li_(9.54)Si_(1.74)P_(1.44)S_(11.7)Cl_(0.3); Li₁₀Si_(0.5)Ge_(0.5)P₂S₁₂;Li₁₀Sn_(0.5)Ge_(0.5)P₂S₁₂; Li₁₀Si_(0.5)Sn_(0.5)P₂S₁₂;Li₁₀GeP₂S_(11.7)O_(0.3); Li_(9.6)P₃S₁₂; Li₉P₃S₉O₃;Li_(10.35)Ge_(1.35)P_(1.65)S₁₂; Li_(10.35)Si_(1.35)P_(1.65)S₁₂;Li_(9.81)Sn_(0.81)P_(2.19)S₁₂;Li_(9.42)Si_(1.02)P_(2.1)S_(9.96)O_(2.04); Li₁₀GeP₂S₁₂; Li₁₃GeP₃S₁₂;Li₁₀SnP₂S₁₂, or mixtures thereof. Particularly preferable lithium metalsulfide, solid-electrolytic phases include Li_(x)M_(y)S_(z) where Mincludes B and/or P, where x, y, and z are positive integers; andLi_(x′)M_(y′)S_(z′)R_(n′) where M includes B and/or P, where R is ahalide, preferably selected from Cl and Br, and where x′, y′, z′, and n′are positive integers.

Notably, the solid-electrolyte particles and the solid-electrolyticphase can have different ratios of M (e.g., B/P) to S. For example, thesolid-electrolyte particles can be solid-sulfide-electrolytenanoparticles which have a formula of Li_(x)M_(y)S_(z) where M includesB and/or P, where x, y, and z are positive integers, and have anelectrolyte nanoparticle S to M ratio of z:y; where thesolid-electrolytic phase then can have a formula of Li_(x′)M_(y′)S_(z′)where M includes B and/or P, and where x′, y′, and z′ are positiveintegers, and has an electrolyte phase S to M ratio of z′:y′.Accordingly, the solid-electrolytic phase S to M ratio is greater(includes more sulfur) than the solid-sulfide-electrolyte nanoparticle Sto M ratio. The solid-sulfide-electrolyte nanoparticles and thesolid-electrolytic phase can further feature a formula where M furtherincludes As, Ge, Ga, Sb, Si, Sn, Al, In, Ti, V, Nb, Ta, and/or Zn. Thatis, in addition to B and/or P. Preferably. M includes Si, Sn, Ge, and/orZn. In another example, the solid-electrolyte particles can besolid-sulfide-electrolyte nanoparticles which have a formula ofLi_(x)M_(y)S_(z)R_(n), where M includes B and/or P, where R is a halide(e.g., Cl or Br), and where x, y, z, and n are positive integers, andhave an electrolyte nanoparticle S to M ratio of z:y; where thesolid-electrolytic phase can then have a formula ofLi_(x′)M_(y′)S_(z′)R_(n′) where M includes B and/or P, where R is ahalide (e.g., Cl or Br), and where x′, y′, z′, and n′ are positiveintegers, and has an electrolyte phase S to M ratio of z′:y′.Accordingly, the solid-electrolytic phase S to M ratio is greater(includes more sulfur) than the solid-sulfide-electrolyte nanoparticle Sto M ratio. In another instance, the solid-electrolytic phase caninclude about 0.01 at. % to about 20 at. %, about 0.01 at. % to about 15at. %, about 0.01 at. % to about 10 at. %, about 0.01 at. % to about 5at. %, or about 0.01 at. % to about 2.5 at. % more sulfur than thesolid-electrolyte nanoparticle.

The solid-electrolyte particulates can have a plurality of sizes butpreferably the solid-electrolyte particulates have an average particlediameter of about 5 nm to about 250 nm, or an average diameter of fromabout 5 nm, 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50nm, 55 nm, 60 nm, 65 nm, 70 nm, 75 nm, 80 nm, 85 nm, 90 nm, or 100 nm toabout 100 nm, 150 nm, 200 nm, 250 nm, 300 nm, 350 nm, 400 nm, 450 nm,500 nm.

The polysulfide can be a lithium polysulfide, a sodium polysulfide, anammonium polysulfide, an alkylammonium polysulfide, or a mixturethereof. The polysulfide is preferably a lithium polysulfide having theformula Li₂S_(x) where x is in the range of 1 to about 24, preferably, 2to about 18, 2 to about 12, 2 to about 10, 2 to about 8, 2 to about 6,or 2 to about 4. The solvent, or polysulfide solution solvent, can bewater (e.g., an ammonium hydroxide solution) or an ether, preferably,the solvent is an ether. The ether can be selected from tetrahydrofuran(THF), tetrahydropyran, 2,2,5,5-tetramethyl tetrahydrofuran, 2-methyltetrahydrofuran, methyl t-butyl ether, ethyl t-butyl ether, 1,4-dioxane,1,3-dioxane, dimethoxyethane, diisopropylether, dibutyl ether, diethylether, and mixtures thereof. In one preferable instance, the solvent isTHF. In another preferable instance, the solvent is dimethoxyethane. Instill another preferable instance, the solvent is 1,4-dioxane. In yetanother preferable instance, the solvent is tetrahydropyran.

In another instance, the polysulfide in the solution includes a sulfurcompound and a solvent. The sulfur compound can be sulfur (elementalsulfur, e.g. S₈ or S₇), phosphorous pentasulfide (P₂S₅ or P₄S₁₀), boronsulfide (B₂S₃), or a mixture thereof. In one preferably instance, thesulfur compound is elemental sulfur. In another preferable instance, thesulfur compound is phosphorus pentasulfide when the solid-electrolytenanoparticles include lithium phosphorous sulfides; and is boron sulfidewhen the solid-electrolyte nanoparticles include lithium boron sulfides.In yet another example, the sulfur compound can be phosphoruspentasulfide when the solid-electrolyte nanoparticles include lithiumboron sulfides; and can be boron sulfide when the solid-electrolytenanoparticles include lithium phosphorous sulfides. In this instance,the solvent is preferably one that can dissolve the sulfur compound.Accordingly, the solvent can be selected from carbon disulfide,pyridine, and a mixture thereof. In one preferable instance, the solventis carbon disulfide. In another instance, wherein the sulfur compound isphosphorous pentasulfide and/or boron sulfide, the solvent can bepyridine.

The solution, preferably, includes about 1 wt. % to about 50 wt. %polysulfide and about 50 wt. % to about 99 wt. % solid-electrolyteparticulate on a dry basis. In another example, the solution includesabout 1 wt. % to about 25 wt. % polysulfide and about 75 wt. % to about99 wt. % solid-electrolyte particulate on a dry basis.

A third embodiment is a composite laminate carried on a currentcollector, the composite laminate preferably includes a plurality ofcomposite active particulates carried in a solid-electrolytic continuousphase. Herewith, the composite laminate preferably includes thecomposite active particulates as described above and further includes asolid-electrolytic phase extending between (i.e. is continuous in thelaminate) the composite active particulates. In one preferable instance,the solid-electrolytic phase both extends between the composite activeparticulates and penetrates the composite active particulates. Putanother way, the solid-electrolytic phase is preferably carried withinthe pores of the individual composite active particulates and betweenthe composite active particulates. While the features of the specificcomponents of the composite of active particulates in thesolid-electrolytic phase are described above, the anode can furtherinclude a conductive carbon carried by the solid-electrolytic phase andbetween the active particulates. In another instance, thesolid-electrolytic continuous phase and the solid-electrolytic phasecarried in the pores can have different compositions. Independent on thecomposition of the phases, the solid-electrolytic continuous phase ispreferably ionically connected to the solid-electrolytic phase carriedin the pores of the heterogeneous matrix. That is, phases provide anionic pathway for, for example, lithium ions to traverse the laminateand penetrate the active particulates. In another preferable instance,the solid-electrolytic continuous phase is covalently affixed to thesolid-electrolytic phase carried in the pores of the heterogeneousmatrix.

A fourth embodiment is a process for preparing an anode (e.g. the abovedescribed composite laminate) for use in a lithium ion battery. Theprocess, analogous to the process of forming the composite activeparticulate described above, can include admixing an active particulateand a solution thereby allowing the solution to penetrate pores of theactive particulate. Thereafter, this admixture of the active particulateand the solution can be coated onto a current collector thereby forminga coating on the current collector. The solvent can then be removed fromthe coating on the current collector thereby providing a compositelaminate that includes the composite active particulates and asolid-electrolytic phase carried on the current collector.

The admixture of the active particulate and the solution, preferablyincludes a ratio of the active particulate to the solid-electrolyteparticulates of about 10:1, about 9:1, about 8:1, about 7:1, about 6:1about 5:1 about 4:1, about 3:1, about 2:1, about 1:1, about 1:2, about1:3, about 1:4, about 1:5, about 1:6, about 1:7, about 1:8, about 1:9,or about 1:10 on a dry basis. The ratio of the active particulate to thesolid-electrolyte particulates can, alternatively, be in the range ofabout 10:1, about 9:1, about 8:1, about 7:1, about 6:1 about 5:1 about4:1, about 3:1, about 2:1, about 1:1, to about 1:2, about 1:3, about1:4, about 1:5, about 1:6, about 1:7, about 1:8, about 1:9, or about1:10 on a dry basis. Preferably, the ratio is about 2:1 to about 1:10,about 1:1 to about 1:5, about 1:1 to about 1:4, about 1:1 to about 1:3,or about 1:1 to about 1:2.

While the compositions and methods of this invention have been describedin terms of preferred embodiments, it will be apparent to those of skillin the art that variations may be applied to the compositions and/ormethods in the steps or in the sequence of steps of the method describedherein without departing from the concept, spirit and scope of theinvention. More specifically, it will be apparent that certain agentsthat are both chemically and physically related may be substituted forthe agents described herein while the same or similar results would beachieved. All such similar substitutes and modifications apparent tothose skilled in the art are deemed to be within the spirit, scope andconcept of the invention as defined by the appended claims.

1. (canceled)
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 13. A process for preparing a composite activeparticulate comprising: providing an active particulate that includes aporous heterogeneous matrix, the porous heterogeneous matrix including acarbon phase carrying and/or having embedded therein a plurality ofsilicon nanoparticles, and a plurality of pores therewithin; providing asolution which includes a polysulfide, a solid-electrolyte particulate,and a solvent; admixing the active particulate and the solution therebyallowing the solution to penetrate pores of the active particulate; andthereafter removing the solvent.
 14. The process of claim 13, whereinthe solid-electrolyte particulates have an average particle diameter ofabout 5 nm to about 250 nm.
 15. The process of claim 13, wherein thesolid-electrolyte particulates have a formula of Li_(x)M_(y)S_(z) orLi_(x)M_(y)S_(z)R_(n) where M includes B and/or P, where R is a halide,and where x, y, z, and n are positive integers.
 16. The process of claim13, wherein the polysulfide includes a lithium polysulfide.
 17. Theprocess of claim 16, wherein after removing the solvent from theadmixture, the process further includes evaporating sulfur from thecomposite active particulate.
 18. The process of claim 13, wherein thesolution includes about 1 wt. % to about 50 wt. % polysulfide and about50 wt. % to about 99 wt. % solid-electrolyte particulate on a dry basis.19. The process of claim 13, wherein removing the solvent includesheating the admixture to a temperature from about 30° C. to about 300°C.
 20. A process for preparing an anode comprising: providing aplurality of active particulates that include a porous heterogeneousmatrix, the porous heterogeneous matrix including a carbon phasecarrying and/or having embedded therein a plurality of siliconnanoparticles, and a plurality of pores therewithin; providing asolution which includes a polysulfide, a solid-electrolyte particulate,and a solvent; admixing the active particulate and the solution therebyallowing the solution to penetrate pores of the active particulate;thereafter coating a current collector with the admixture of the activeparticulate and the solution thereby forming a coating on the currentcollector; and then removing the solvent from the coating on the currentcollector and thereby providing a composite laminate that includescomposite active particulates in a solid-electrolytic continuous phasecarried on the current collector, wherein the composite activeparticulates include a solid-electrolytic phase carried within the poresof the porous heterogeneous matrix, and wherein the solid-electrolyticphase is covalently affixed to the solid-electrolytic continuous phase.